<?php

/**
 * Underscore.php v1.3.1
 * Copyright (c) 2011 Brian Haveri
 * Underscore.php is licensed under the MIT license
 * Underscore.php was inspired by and borrowed from Underscore.js
 * For docs, license, tests, and downloads, see: http://brianhaveri.github.com/Underscore.php
 */

// Underscore.php
class __ {

    // Start the chain
    private $_chained = false; // Are we in a chain?
    public function chain($item=null) {
        list($item) = self::_wrapArgs(func_get_args(), 1);

        $__ = (isset($this) && isset($this->_chained) && $this->_chained) ? $this : __($item);
        $__->_chained = true;
        return $__;
    }


    // End the chain
    public function value() {
        return (isset($this)) ? $this->_wrapped : null;
    }


    // Invoke the iterator on each item in the collection
    public function each($collection=null, $iterator=null) {
        list($collection, $iterator) = self::_wrapArgs(func_get_args(), 2);

        if(is_null($collection)) return self::_wrap(null);

        $collection = (array) self::_collection($collection);
        if(count($collection) === 0) return self::_wrap(null);

        foreach($collection as $k=>$v) {
            call_user_func($iterator, $v, $k, $collection);
        }
        return self::_wrap(null);
    }


    // Return an array of values by mapping each item through the iterator
    // map alias: collect
    public function collect($collection=null, $iterator=null) { return self::map($collection, $iterator); }
    public function map($collection=null, $iterator=null) {
        list($collection, $iterator) = self::_wrapArgs(func_get_args(), 2);

        if(is_null($collection)) return self::_wrap(array());

        $collection = (array) self::_collection($collection);
        if(count($collection) === 0) self::_wrap(array());

        $return = array();
        foreach($collection as $k=>$v) {
            $return[] = call_user_func($iterator, $v, $k, $collection);
        }
        return self::_wrap($return);
    }


    // Reduce a collection to a single value
    // reduce aliases: foldl, inject
    public function foldl($collection=null, $iterator=null, $memo=null) { return self::reduce($collection, $iterator, $memo); }
    public function inject($collection=null, $iterator=null, $memo=null) { return self::reduce($collection, $iterator, $memo); }
    public function reduce($collection=null, $iterator=null, $memo=null) {
        list($collection, $iterator, $memo) = self::_wrapArgs(func_get_args(), 3);

        if(!is_object($collection) && !is_array($collection)) {
            if(is_null($memo)) throw new Exception('Invalid object');
            else return self::_wrap($memo);
        }

        return self::_wrap(array_reduce($collection, $iterator, $memo));
    }


    // Right-associative version of reduce
    // reduceRight alias: foldr
    public function foldr($collection=null, $iterator=null, $memo=null) { return self::reduceRight($collection, $iterator, $memo); }
    public function reduceRight($collection=null, $iterator=null, $memo=null) {
        list($collection, $iterator, $memo) = self::_wrapArgs(func_get_args(), 3);

        if(!is_object($collection) && !is_array($collection)) {
            if(is_null($memo)) throw new Exception('Invalid object');
            else return self::_wrap($memo);
        }

        krsort($collection);

        $__ = new self;
        return self::_wrap($__->reduce($collection, $iterator, $memo));
    }


    // Extract an array of values for a given property
    public function pluck($collection=null, $key=null) {
        list($collection, $key) = self::_wrapArgs(func_get_args(), 2);

        $collection = (array) self::_collection($collection);

        $return = array();
        foreach($collection as $item) {
            foreach($item as $k=>$v) {
                if($k === $key) $return[] = $v;
            }
        }
        return self::_wrap($return);
    }


    // Does the collection contain this value?
    // includ alias: contains
    public function contains($collection=null, $val=null) { return self::includ($collection, $val); }
    public function includ($collection=null, $val=null) {
        list($collection, $val) = self::_wrapArgs(func_get_args(), 2);

        $collection = (array) self::_collection($collection);

        return self::_wrap((array_search($val, $collection, true) !== false));
    }


    // Invoke the named function over each item in the collection, optionally passing arguments to the function
    public function invoke($collection=null, $function_name=null, $arguments=null) {
        $args = self::_wrapArgs(func_get_args(), 2);
        $__ = new self;
        list($collection, $function_name) = $__->first($args, 2);
        $arguments = $__->rest(func_get_args(), 2);

        // If passed an array or string, return an array
        // If passed an object, return an object
        $is_obj = is_object($collection);
        $result = (empty($arguments)) ? array_map($function_name, (array) $collection) : array_map($function_name, (array) $collection, $arguments);
        if($is_obj) $result = (object) $result;

        return self::_wrap($result);
    }


    // Does any values in the collection meet the iterator's truth test?
    // any alias: some
    public function some($collection=null, $iterator=null) { return self::any($collection, $iterator); }
    public function any($collection=null, $iterator=null) {
        list($collection, $iterator) = self::_wrapArgs(func_get_args(), 2);

        $collection = self::_collection($collection);

        $__ = new self;
        if(!is_null($iterator)) $collection = $__->map($collection, $iterator);
        if(count($collection) === 0) return self::_wrap(false);

        return self::_wrap(is_int(array_search(true, $collection, false)));
    }


    // Do all values in the collection meet the iterator's truth test?
    // all alias: every
    public function every($collection=null, $iterator=null) { return self::all($collection, $iterator); }
    public function all($collection=null, $iterator=null) {
        list($collection, $iterator) = self::_wrapArgs(func_get_args(), 2);

        $collection = self::_collection($collection);

        $__ = new self;
        if(!is_null($iterator)) $collection = $__->map($collection, $iterator);
        $collection = (array) $collection;
        if(count($collection) === 0) return true;

        return self::_wrap(is_bool(array_search(false, $collection, false)));
    }


    // Return an array of values that pass the truth iterator test
    // filter alias: select
    public function select($collection=null, $iterator=null) { return self::filter($collection, $iterator); }
    public function filter($collection=null, $iterator=null) {
        list($collection, $iterator) = self::_wrapArgs(func_get_args(), 2);

        $collection = self::_collection($collection);

        $return = array();
        foreach($collection as $val) {
            if(call_user_func($iterator, $val)) $return[] = $val;
        }
        return self::_wrap($return);
    }


    // Return an array where the items failing the truth test are removed
    public function reject($collection=null, $iterator=null) {
        list($collection, $iterator) = self::_wrapArgs(func_get_args(), 2);

        $collection = self::_collection($collection);

        $return = array();
        foreach($collection as $val) {
            if(!call_user_func($iterator, $val)) $return[] = $val;
        }
        return self::_wrap($return);
    }


    // Return the value of the first item passing the truth iterator test
    // find alias: detect
    public function detect($collection=null, $iterator=null) { return self::find($collection, $iterator); }
    public function find($collection=null, $iterator=null) {
        list($collection, $iterator) = self::_wrapArgs(func_get_args(), 2);

        $collection = self::_collection($collection);

        foreach($collection as $val) {
            if(call_user_func($iterator, $val)) return $val;
        }
        return self::_wrap(false);
    }


    // How many items are in this collection?
    public function size($collection=null) {
        list($collection) = self::_wrapArgs(func_get_args(), 1);

        $collection = self::_collection($collection);

        return self::_wrap(count((array) $collection));
    }


    // Get the first element of an array. Passing n returns the first n elements.
    // first alias: head
    public function head($collection=null, $n=null) { return self::first($collection, $n); }
    public function first($collection=null, $n=null) {
        list($collection, $n) = self::_wrapArgs(func_get_args(), 2);

        $collection = self::_collection($collection);

        if($n === 0) return self::_wrap(array());
        if(is_null($n)) return self::_wrap(current(array_splice($collection, 0, 1, true)));
        return self::_wrap(array_splice($collection, 0, $n, true));
    }


    // Get the rest of the array elements. Passing n returns from that index onward.
    public function tail($collection=null, $index=null) { return self::rest($collection, $index); }
    public function rest($collection=null, $index=null) {
        list($collection, $index) = self::_wrapArgs(func_get_args(), 2);
        if(is_null($index)) $index = 1;

        $collection = self::_collection($collection);

        return self::_wrap(array_splice($collection, $index));
    }


    // Return everything but the last array element. Passing n excludes the last n elements.
    public function initial($collection=null, $n=null) {
        list($collection, $n) = self::_wrapArgs(func_get_args(), 2);

        $collection = (array) self::_collection($collection);

        if(is_null($n)) $n = 1;
        $first_index = count($collection) - $n;
        $__ = new self;
        return self::_wrap($__->first($collection, $first_index));
    }


    // Get the last element from an array. Passing n returns the last n elements.
    public function last($collection=null, $n=null) {
        list($collection, $n) = self::_wrapArgs(func_get_args(), 2);
        $collection = self::_collection($collection);

        if($n === 0) $result = array();
        elseif($n === 1 || is_null($n)) $result = array_pop($collection);
        else {
            $__ = new self;
            $result = $__->rest($collection, -$n);
        }

        return self::_wrap($result);
    }


    // Return a copy of the array with falsy values removed
    public function compact($collection=null) {
        list($collection) = self::_wrapArgs(func_get_args(), 1);

        $collection = self::_collection($collection);

        $__ = new self;
        return self::_wrap($__->select($collection, function($val) {
            return (bool) $val;
        }));
    }


    // Flattens a multidimensional array
    public function flatten($collection=null, $shallow=null) {
        list($collection, $shallow) = self::_wrapArgs(func_get_args(), 2);

        $collection = self::_collection($collection);

        $return = array();
        if(count($collection) > 0) {
            foreach($collection as $item) {
                if(is_array($item)) {
                    $__ = new self;
                    $return = array_merge($return, ($shallow) ? $item : $__->flatten($item));
                }
                else $return[] = $item;
            }
        }
        return self::_wrap($return);
    }


    // Returns a copy of the array with all instances of val removed
    public function without($collection=null, $val=null) {
        $args = self::_wrapArgs(func_get_args(), 1);
        $collection = $args[0];
        $collection = self::_collection($collection);

        $num_args = count($args);
        if($num_args === 1) return self::_wrap($collection);
        if(count($collection) === 0) return self::_wrap($collection);

        $__ = new self;
        $removes = $__->rest($args);
        foreach($removes as $remove) {
            $remove_keys = array_keys($collection, $remove, true);
            if(count($remove_keys) > 0) {
                foreach($remove_keys as $key) {
                    unset($collection[$key]);
                }
            }
        }
        return self::_wrap($collection);
    }


    // Return an array of the unique values
    // uniq alias: unique
    public function unique($collection=null, $is_sorted=null, $iterator=null) { return self::uniq($collection, $is_sorted, $iterator); }
    public function uniq($collection=null, $is_sorted=null, $iterator=null) {
        list($collection, $is_sorted, $iterator) = self::_wrapArgs(func_get_args(), 3);

        $collection = self::_collection($collection);

        $return = array();
        if(count($collection) === 0) return self::_wrap($return);

        $calculated = array();
        foreach($collection as $item) {
            $val = (!is_null($iterator)) ? $iterator($item) : $item;
            if(is_bool(array_search($val, $calculated, true))) {
                $calculated[] = $val;
                $return[] = $item;
            }
        }

        return self::_wrap($return);
    }


    // Returns an array containing the intersection of all the arrays
    public function intersection($array=null) {
        $arrays = self::_wrapArgs(func_get_args(), 1);

        if(count($arrays) === 1) return self::_wrap($array);

        $__ = new self;
        $return = $__->first($arrays);
        foreach($__->rest($arrays) as $next) {
            if(!$__->isArray($next)) $next = str_split((string) $next);

            $return = array_intersect($return, $next);
        }

        return self::_wrap(array_values($return));
    }


    // Merge together multiple arrays
    public function union($array=null) {
        $arrays = self::_wrapArgs(func_get_args(), 1);

        if(count($arrays) === 1) return self::_wrap($array);

        $__ = new self;
        return self::_wrap($__->flatten(array_values(array_unique(call_user_func_array('array_merge', $arrays)))));
    }


    // Get the difference between two arrays
    public function difference($array_one=null, $array_two=null) {
        $arrays = self::_wrapArgs(func_get_args(), 1);

        return self::_wrap(array_values(call_user_func_array('array_diff', $arrays)));
    }


    // Get the index of the first match
    public function indexOf($collection=null, $item=null) {
        list($collection, $item) = self::_wrapArgs(func_get_args(), 2);

        $collection = self::_collection($collection);

        $key = array_search($item, $collection, true);
        return self::_wrap((is_bool($key)) ? -1 : $key);
    }


    // Get the index of the last match
    public function lastIndexOf($collection=null, $item=null) {
        list($collection, $item) = self::_wrapArgs(func_get_args(), 2);

        $collection = self::_collection($collection);

        krsort($collection);
        $__ = new self;
        return self::_wrap($__->indexOf($collection, $item));
    }


    // Returns an array of integers from start to stop (exclusive) by step
    public function range($stop=null) {
        $args = self::_wrapArgs(func_get_args(), 1);

        $__ = new self;
        $args = $__->reject($args, function($val) {
            return is_null($val);
        });

        $num_args = count($args);
        switch($num_args) {
            case 1:
                list($start, $stop, $step) = array(0, $args[0], 1);
                break;
            case 2:
                list($start, $stop, $step) = array($args[0], $args[1], 1);
                if($stop < $start) return self::_wrap(array());
                break;
            default:
                list($start, $stop, $step) = array($args[0], $args[1], $args[2]);
                if($step > 0 && $step > $stop) return self::_wrap(array($start));
        }
        $results = range($start, $stop, $step);

        // Switch inclusive to exclusive
        if($step > 0 && $__->last($results) >= $stop) array_pop($results);
        elseif($step < 0 && $__->last($results) <= $stop) array_pop($results);

        return self::_wrap($results);
    }


    // Merges arrays
    public function zip($array=null) {
        $arrays = self::_wrapArgs(func_get_args());
        $num_arrays = count($arrays);
        if($num_arrays === 1) return self::_wrap($array);

        $__ = new self;
        $num_return_arrays = $__->max($__->map($arrays, function($array) {
            return count($array);
        }));
        $return_arrays = $__->range($num_return_arrays);
        foreach($return_arrays as $k=>$v) {
            if(!is_array($return_arrays[$k])) $return_arrays[$k] = array();

            foreach($arrays as $a=>$array) {
                $return_arrays[$k][$a] = array_key_exists($k, $array) ? $array[$k] : null;
            }
        }

        return self::_wrap($return_arrays);
    }


    // Get the max value in the collection
    public function max($collection=null, $iterator=null) {
        list($collection, $iterator) = self::_wrapArgs(func_get_args(), 2);

        if(is_null($iterator)) return self::_wrap(max($collection));

        $results = array();
        foreach($collection as $k=>$item) {
            $results[$k] = $iterator($item);
        }
        arsort($results);
        $__ = new self;
        $first_key = $__->first(array_keys($results));
        return $collection[$first_key];
    }


    // Get the min value in the collection
    public function min($collection=null, $iterator=null) {
        list($collection, $iterator) = self::_wrapArgs(func_get_args(), 2);

        if(is_null($iterator)) return self::_wrap(min($collection));

        $results = array();
        foreach($collection as $k=>$item) {
            $results[$k] = $iterator($item);
        }
        asort($results);
        $__ = new self;
        $first_key = $__->first(array_keys($results));
        return self::_wrap($collection[$first_key]);
    }


    // Sort the collection by return values from the iterator
    public function sortBy($collection=null, $iterator=null) {
        list($collection, $iterator) = self::_wrapArgs(func_get_args(), 2);

        $results = array();
        foreach($collection as $k=>$item) {
            $results[$k] = $iterator($item);
        }
        asort($results);
        foreach($results as $k=>$v) {
            $results[$k] = $collection[$k];
        }
        return self::_wrap(array_values($results));
    }


    // Group the collection by return values from the iterator
    public function groupBy($collection=null, $iterator=null) {
        list($collection, $iterator) = self::_wrapArgs(func_get_args(), 2);

        $result = array();
        $collection = (array) $collection;
        foreach($collection as $k=>$v) {
            $key = (is_callable($iterator)) ? $iterator($v, $k) : $v[$iterator];
            if(!array_key_exists($key, $result)) $result[$key] = array();
            $result[$key][] = $v;
        }
        return $result;
    }


    // Returns the index at which the value should be inserted into the sorted collection
    public function sortedIndex($collection=null, $value=null, $iterator=null) {
        list($collection, $value, $iterator) = self::_wrapArgs(func_get_args(), 3);

        $collection = (array) self::_collection($collection);
        $__ = new self;

        $calculated_value = (!is_null($iterator)) ? $iterator($value) : $value;

        while(count($collection) > 1) {
            $midpoint = floor(count($collection) / 2);
            $midpoint_values = array_slice($collection, $midpoint, 1);
            $midpoint_value = $midpoint_values[0];
            $midpoint_calculated_value = (!is_null($iterator)) ? $iterator($midpoint_value) : $midpoint_value;

            $collection = ($calculated_value < $midpoint_calculated_value) ? array_slice($collection, 0, $midpoint, true) : array_slice($collection, $midpoint, null, true);
        }
        $keys = array_keys($collection);

        return self::_wrap(current($keys) + 1);
    }

    // Shuffle the array
    public function shuffle($collection=null) {
        list($collection) = self::_wrapArgs(func_get_args(), 1);

        $collection = (array) self::_collection($collection);
        shuffle($collection);

        return self::_wrap($collection);
    }


    // Return the collection as an array
    public function toArray($collection=null) {
        return (array) $collection;
    }


    // Get the collection's keys
    public function keys($collection=null) {
        list($collection) = self::_wrapArgs(func_get_args(), 1);

        if(!is_object($collection) && !is_array($collection)) throw new Exception('Invalid object');

        return self::_wrap(array_keys((array) $collection));
    }


    // Get the collection's values
    public function values($collection=null) {
        list($collection) = self::_wrapArgs(func_get_args(), 1);

        return self::_wrap(array_values((array) $collection));
    }


    // Copy all properties from the source objects into the destination object
    public function extend($object=null) {
        $args = self::_wrapArgs(func_get_args(), 1);

        $num_args = func_num_args();
        if($num_args === 1) return $object;

        $is_object = is_object($object);
        $array = (array) $object;
        $__ = new self;
        $extensions = $__->rest(func_get_args());
        foreach($extensions as $extension) {
            $extension = (array) $extension;
            $array = array_merge($array, $extension);
        }
        return self::_wrap(($is_object) ? (object) $array : $array);
    }


    // Returns the object with any missing values filled in using the defaults.
    public function defaults($object=null) {
        $args = self::_wrapArgs(func_get_args(), 1);
        list($object) = $args;

        $num_args = count($args);
        if($num_args === 1) return $object;

        $is_object = is_object($object);
        $array = (array) $object;
        $__ = new self;
        $extensions = $__->rest($args);
        foreach($extensions as $extension) {
            $extension = (array) $extension;
            $array = array_merge($extension, $array);
        }
        return self::_wrap(($is_object) ? (object) $array : $array);
    }


    // Get the names of functions available to the object
    // functions alias: methods
    public function methods($object=null) { return self::functions($object); }
    public function functions($object=null) {
        list($object) = self::_wrapArgs(func_get_args(), 1);

        return self::_wrap(get_class_methods(get_class($object)));
    }


    // Returns a shallow copy of the object
    public function clon(&$object=null) {
        list($object) = self::_wrapArgs(func_get_args(), 1);

        $clone = null;
        if(is_array($object)) $clone = (array) clone (object) $object;
    elseif(!is_object($object)) $clone = $object;
    elseif(!$clone) $clone = clone $object;
    
    // shallow copy object
    if(is_object($clone) && count($clone) > 0) {
        foreach($clone as $k=>$v) {
            if(is_array($v) || is_object($v)) $clone->$k =& $object->$k;
        }
    }

    // shallow copy array
    elseif(is_array($clone) && count($clone) > 0) {
        foreach($clone as $k=>$v) {
            if(is_array($v) || is_object($v)) $clone[$k] =& $object[$k];
        }
    }
    return self::_wrap($clone);
  }


    // Invokes the interceptor on the object, then returns the object
    public function tap($object=null, $interceptor=null) {
        list($object, $interceptor) = self::_wrapArgs(func_get_args(), 2);

        $interceptor($object);
        return self::_wrap($object);
    }


    // Does the given key exist?
    public function has($collection=null, $key=null) {
        list($collection, $key) = self::_wrapArgs(func_get_args(), 2);

        $collection = (array) self::_collection($collection);

        return self::_wrap(array_key_exists($key, $collection));
    }


    // Are these items equal?
    public function isEqual($a=null, $b=null) {
        list($a, $b) = self::_wrapArgs(func_get_args(), 2);

        if(isset($this) && isset($this->_chained) && $this->_chained) $a =& $this;

        if($a === $b) return self::_wrap(true);
        if(gettype($a) !== gettype($b)) return self::_wrap(false);
        if(is_callable($a) !== is_callable($b)) return self::_wrap(false);

        if($a == $b) return self::_wrap(true);

        // Objects and arrays compared by values
        if(is_object($a) || is_array($a)) {

            // Do either implement isEqual()?
            if(is_object($a) && isset($a->isEqual)) return self::_wrap($a->isEqual($b));
            if(is_object($b) && isset($b->isEqual)) return self::_wrap($b->isEqual($a));
            if(is_array($a) && array_key_exists('isEqual', $a)) return self::_wrap($a['isEqual']($b));
            if(is_array($b) && array_key_exists('isEqual', $b)) return self::_wrap($b['isEqual']($a));

            if(count($a) !== count($b)) return self::_wrap(false);

            $__ = new self;
            $keys_equal = $__->isEqual($__->keys($a), $__->keys($b));
            $values_equal = $__->isEqual($__->values($a), $__->values($b));
            return self::_wrap($keys_equal && $values_equal);
        }

        return self::_wrap(false);
    }


    // Is this item empty?
    public function isEmpty($item=null) {
        list($item) = self::_wrapArgs(func_get_args(), 1);

        return self::_wrap(is_array($item) || is_object($item)) ? !((bool) count((array) $item)) : (!(bool) $item);
    }


    // Is this item an object?
    public function isObject($item=null) {
        list($item) = self::_wrapArgs(func_get_args(), 1);
        return self::_wrap(is_object($item));
    }


    // Is this item an array?
    public function isArray($item=null) {
        list($item) = self::_wrapArgs(func_get_args(), 1);
        return self::_wrap(is_array($item));
    }


    // Is this item a string?
    public function isString($item=null) {
        list($item) = self::_wrapArgs(func_get_args(), 1);
        return self::_wrap(is_string($item));
    }


    // Is this item a number?
    public function isNumber($item=null) {
        list($item) = self::_wrapArgs(func_get_args(), 1);
        return self::_wrap((is_int($item) || is_float($item)) && !is_nan($item) && !is_infinite($item));
    }


    // Is this item a bool?
    public function isBoolean($item=null) {
        list($item) = self::_wrapArgs(func_get_args(), 1);
        return self::_wrap(is_bool($item));
    }


    // Is this item a function (by type, not by name)?
    public function isFunction($item=null) {
        list($item) = self::_wrapArgs(func_get_args(), 1);
        return self::_wrap(is_object($item) && is_callable($item));
    }


    // Is this item an instance of DateTime?
    public function isDate($item=null) {
        list($item) = self::_wrapArgs(func_get_args(), 1);
        return self::_wrap(is_object($item) && get_class($item) === 'DateTime');
    }


    // Is this item a NaN value?
    public function isNaN($item=null) {
        list($item) = self::_wrapArgs(func_get_args(), 1);
        return self::_wrap(is_nan($item));
    }


    // Returns the same value passed as the argument
    public function identity() {
        $args = self::_wrapArgs(func_get_args(), 1);

        if(is_array($args)) return self::_wrap($args[0]);

        return self::_wrap(function($x) {
            return $x;
        });
    }


    // Generate a globally unique id, optionally prefixed
    public $_uniqueId = -1;
    public function uniqueId($prefix=null) {
        list($prefix) = self::_wrapArgs(func_get_args(), 1);

        $_instance = self::getInstance();
        $_instance->_uniqueId++;

        return (is_null($prefix)) ? self::_wrap($_instance->_uniqueId) : self::_wrap($prefix . $_instance->_uniqueId);
    }


    // Invokes the iterator n times
    public function times($n=null, $iterator=null) {
        list($n, $iterator) = self::_wrapArgs(func_get_args(), 2);
        if(is_null($n)) $n = 0;

        for($i=0; $i<$n; $i++) $iterator($i);
        return self::_wrap(null);
    }


    // Extend the class with your own functions
    private $_mixins = array();
    public function mixin($functions=null) {
        list($functions) = self::_wrapArgs(func_get_args(), 1);

        $mixins =& self::getInstance()->_mixins;
        foreach($functions as $name=>$function) {
            $mixins[$name] = $function;
        }
        return self::_wrap(null);
    }


    // Allows extending methods in static context
    public static function __callStatic($name, $arguments) {
        $mixins =& self::getInstance()->_mixins;
        return call_user_func_array($mixins[$name], $arguments);
    }

    // Allows extending methods in non-static context
    public function __call($name, $arguments) {
        $mixins =& self::getInstance()->_mixins;
        $arguments = self::_wrapArgs($arguments);
        return call_user_func_array($mixins[$name], $arguments);
    }


    // Temporary PHP open and close tags used within templates
    // Allows for normal processing of templates even when
    // the developer uses PHP open or close tags for interpolation or evaluation
    const TEMPLATE_OPEN_TAG = '760e7dab2836853c63805033e514668301fa9c47';
    const TEMPLATE_CLOSE_TAG= 'd228a8fa36bd7db108b01eddfb03a30899987a2b';

    const TEMPLATE_DEFAULT_EVALUATE   = '/<%([\s\S]+?)%>/';
    const TEMPLATE_DEFAULT_INTERPOLATE= '/<%=([\s\S]+?)%>/';
    const TEMPLATE_DEFAULT_ESCAPE     = '/<%-([\s\S]+?)%>/';
    public $_template_settings = array(
        'evaluate'    => self::TEMPLATE_DEFAULT_EVALUATE,
        'interpolate' => self::TEMPLATE_DEFAULT_INTERPOLATE,
        'escape'      => self::TEMPLATE_DEFAULT_ESCAPE
    );

    // Set template settings
    public function templateSettings($settings=null) {
        $_template_settings =& self::getInstance()->_template_settings;

        if(is_null($settings)) {
            $_template_settings = array(
                'evaluate'    => self::TEMPLATE_DEFAULT_EVALUATE,
                'interpolate' => self::TEMPLATE_DEFAULT_INTERPOLATE,
                'escape'      => self::TEMPLATE_DEFAULT_ESCAPE
            );
            return true;
        }

        foreach($settings as $k=>$v) {
            if(!array_key_exists($k, $_template_settings)) continue;

            $_template_settings[$k] = $v;
        }
        return true;
    }


    // Compile templates into functions that can be evaluated for rendering
    public function template($code=null, $context=null) {
        list($code, $context) = self::_wrapArgs(func_get_args(), 2);

        $class_name = __CLASS__;

        $return = self::_wrap(function($context=null) use ($code, $class_name) {
            $ts = $class_name::getInstance()->_template_settings;

            // Wrap escaped, interpolated, and evaluated blocks inside PHP tags
            extract((array) $context);
            preg_match_all($ts['escape'], $code, $vars, PREG_SET_ORDER);
            if(count($vars) > 0) {
                foreach($vars as $var) {
                    $echo = $class_name::TEMPLATE_OPEN_TAG . ' echo htmlentities(' . trim($var[1]) . '); ' . $class_name::TEMPLATE_CLOSE_TAG;
                    $code = str_replace($var[0], $echo, $code);
                }
            }
            preg_match_all($ts['interpolate'], $code, $vars, PREG_SET_ORDER);
            if(count($vars) > 0) {
                foreach($vars as $var) {
                    $echo = $class_name::TEMPLATE_OPEN_TAG . ' echo ' . trim($var[1]) . '; ' . $class_name::TEMPLATE_CLOSE_TAG;
                    $code = str_replace($var[0], $echo, $code);
                }
            }
            preg_match_all($ts['evaluate'], $code, $vars, PREG_SET_ORDER);
            if(count($vars) > 0) {
                foreach($vars as $var) {
                    $echo = $class_name::TEMPLATE_OPEN_TAG . trim($var[1]) . $class_name::TEMPLATE_CLOSE_TAG;
                    $code = str_replace($var[0], $echo, $code);
                }
            }
            $code = str_replace($class_name::TEMPLATE_OPEN_TAG, '<?php ', $code);
            $code = str_replace($class_name::TEMPLATE_CLOSE_TAG, '?>', $code);

            // Use the output buffer to grab the return value
            $code = 'ob_start(); extract($context); ?>' . $code . '<?php return ob_get_clean();';

            $func = create_function('$context', $code);
            return $func((array) $context);
        });

        // Return function or call function depending on context
        return self::_wrap(((isset($this) && isset($this->_wrapped) && $this->_wrapped) || !is_null($context)) ? $return($context) : $return);
    }

    // Escape
    public function escape($item=null) {
        list($item) = self::_wrapArgs(func_get_args(), 1);

        return self::_wrap(htmlentities($item));
    }


    // Memoizes a function by caching the computed result.
    public $_memoized = array();
    public function memoize($function=null, $hashFunction=null) {
        list($function, $hashFunction) = self::_wrapArgs(func_get_args(), 2);

        $_instance = (isset($this) && isset($this->_wrapped)) ? $this : self::getInstance();

        return self::_wrap(function() use ($function, &$_instance, $hashFunction) {

            // Generate a key based on hashFunction
            $args = func_get_args();
            if(is_null($hashFunction)) $hashFunction = function($function, $args) {

                // Try using var_export to identify the function
                return md5(join('_', array(
                    var_export($function, true),
                    var_export($args, true)
                )));
            };
            $key = $hashFunction($function, $args);

            if(!array_key_exists($key, $_instance->_memoized)) {
                $_instance->_memoized[$key] = call_user_func_array($function, $args);
            }
            return $_instance->_memoized[$key];
        });
    }


    // Throttles a function so that it can only be called once every wait milliseconds
    public $_throttled = array();
    public function throttle($function=null, $wait=null) {
        list($function, $wait) = self::_wrapArgs(func_get_args(), 2);

        $_instance = (isset($this) && isset($this->_wrapped)) ? $this : self::getInstance();

        return self::_wrap(function() use ($function, $wait, &$_instance) {

            // Try using var_export to identify the function
            $key = md5(join('', array(
                var_export($function, true),
                $wait
            )));

            $microtime = microtime(true);
            $ready_to_call = (!array_key_exists($key, $_instance->_throttled) || $microtime >= $_instance->_throttled[$key]);
            if($ready_to_call) {
                $next_callable_time = $microtime + ($wait / 1000);
                $_instance->_throttled[$key] = $next_callable_time;
                return call_user_func_array($function, func_get_args());
            }
        });
    }


    // Creates a version of the function that can only be called once
    public $_onced = array();
    public function once($function=null) {
        list($function) = self::_wrapArgs(func_get_args(), 1);

        $_instance = (isset($this) && isset($this->_wrapped)) ? $this : self::getInstance();

        return self::_wrap(function() use ($function, &$_instance) {

            // Try using var_export to identify the function
            $key = md5(var_export($function, true));
            if(!array_key_exists($key, $_instance->_onced)) {
                $_instance->_onced[$key] = call_user_func_array($function, func_get_args());
            }

            return $_instance->_onced[$key];
        });
    }


    // Wraps the function inside the wrapper function, passing it as the first argument
    public function wrap($function=null, $wrapper=null) {
        list($function, $wrapper) = self::_wrapArgs(func_get_args(), 2);

        return self::_wrap(function() use ($wrapper, $function) {
            $args = array_merge(array($function), func_get_args());
            return call_user_func_array($wrapper, $args);
        });
    }


    // Returns the composition of the functions
    public function compose() {
        $functions = self::_wrapArgs(func_get_args(), 1);

        return self::_wrap(function() use ($functions) {
            $args = func_get_args();
            foreach($functions as $function) {
                $args[0] = call_user_func_array($function, $args);
            }
            return $args[0];
        });
    }


    // Creates a version of the function that will only run after being called count times
    public $_aftered = array();
    public function after($count=null, $function=null) {
        list($count, $function) = self::_wrapArgs(func_get_args(), 2);

        $_instance = (isset($this) && isset($this->_wrapped)) ? $this : self::getInstance();
        $key = md5(mt_rand());

        $func = function() use ($function, &$_instance, $count, $key) {
            if(!array_key_exists($key, $_instance->_aftered)) $_instance->_aftered[$key] = 0;
            $_instance->_aftered[$key] += 1;

            if($_instance->_aftered[$key] >= $count) return call_user_func_array($function, func_get_args());
        };
        return self::_wrap(($count) ? $func : $func());
    }


    // Singleton
    private static $_instance;
    public function getInstance() {
        if(!isset(self::$_instance)) {
            $c = __CLASS__;
            self::$_instance = new $c;
        }
        return self::$_instance;
    }


    // All methods should wrap their returns within _wrap
    // because this function understands both OO-style and functional calls
    public $_wrapped; // Value passed from one chained method to the next
    private function _wrap($val) {
        if(isset($this) && isset($this->_chained) && $this->_chained) {
            $this->_wrapped = $val;
            return $this;
        }
        return $val;
    }


    // All methods should get their arguments from _wrapArgs
    // because this function understands both OO-style and functional calls
    private function _wrapArgs($caller_args, $num_args=null) {
        $num_args = (is_null($num_args)) ? count($caller_args) - 1 : $num_args;

        $filled_args = array();
        if(isset($this) && isset($this->_wrapped)) {
            $filled_args[] =& $this->_wrapped;
        }
        if(count($caller_args) > 0) {
            foreach($caller_args as $k=>$v) {
                $filled_args[] = $v;
            }
        }

        return array_pad($filled_args, $num_args, null);
    }


    // Get a collection in a way that supports strings
    private function _collection($collection) {
        return (!is_array($collection) && !is_object($collection)) ? str_split((string) $collection) : $collection;
    }
}
